Eight current and former employees who worked on Netflix's "House of Cards" have accused actor Kevin Spacey of sexual assault.

The accusers in the report allege Spacey created a "toxic" work environment with his "predatory" behaviour on the set of the hit Netflix show, CNN reported.

The allegations include non-consensual touching and crude comments towards staff members, many of them young and male.

One former production assistant alleged to CNN that when he and Spacey were inside a car, Spacey had put his hands down the production assistant's pants without consent. The production assistant went into more detail on what transpired next, but asked for his account to be omitted from the report.

"I was in a state of shock," the production assistant said.

"He was a man in a very powerful position on the show and I was someone very low on the totem pole and on the food chain there," the assistant added.

The production assistant, who alleged that Spacey had previously sexually assaulted him before this incident, said he had notified a supervisor of Spacey's behaviour, who then never allowed the two alone by themselves on the set.

"I have no doubt that this type of predatory behaviour was routine for him and that my experience was one of many and that Kevin had few if any qualms about exploiting his status and position," the production assistant said.

"It was a toxic environment for young men who had to interact with him at all in the crew, cast, background actors."

Another crew member quoted by CNN said Spacey "would put his hands on me in a weird way".

"He would come in and massage my shoulders from behind or put his hands around me or touch my stomach sometimes in weird ways that in normal everyday conversation would not be appropriate," the crew member said.

Other witnesses include a former camera assistant who said "everybody saw" the alleged behaviour by Spacey.

"All the crew members commented on his behaviour. What gets me is we have to sign sexual harassment paperwork before the start of the show and apparently (Kevin Spacey) doesn't have to do anything and he gets away scot-free with this behaviour," the former camera assistant said.

One former female production assistant on the set also said that Spacey's conduct was well-known among the staff.

"It was very known that Kevin was inappropriate, and males I worked with complained to me about how they felt uncomfortable. Kevin does this thing which was play fights with them in order to touch them," she said.

Officials of MRC, the production company for the "House of Cards", have said in a statement that the news has made them "deeply troubled" and that they would provide an "anonymous complaint hotline, crisis counsellors and sexual harassment legal advisors for the crew."